2026 Annual Shareholders’ Meeting Presentation

April 29, 2026

Pure play regulated utility creating long-term sustainable value

Local distributor of electricity and natural gas in Maine, Massachusetts and New Hampshire with attractive service areas

• Fully regulated electric and gas operations

• Growing customer base supported by strong regional economic growth

• Natural gas price advantage over competing fuels

  Robust investment opportunities in electric and natural gas

  infrastructure

• Grid modernization, resiliency, and renewable resource investments are well-aligned with climate policies

• Timely recovery of capital investments

  Stable long-term expected earnings and dividend growth

• Distribution revenues largely decoupled from sales volumes

• Earnings unaffected by commodity cost fluctuations

• Supportive regulatory outcomes

  Compelling investor value proposition

• Low-risk expected earnings and dividend growth

• Sustainable long-term organic growth opportunities

• Proven track record of financial, operating, and strategic performance

  SLIDE 3

  
  
  Turning Promises into Progress

  Delivering strong financial results through superior operational performance

  ✓

  Financial and Strategic Execution

  • Achieved record earnings of $50.2

    million and adjusted EPS(1) of $3.16

  • Increased dividend by 5.6% to $1.90 on an annualized basis

  • Maintained strong balance sheet

    with credit metrics well above peers

  • Closed acquisitions of Bangor Natural Gas and Maine Natural Gas

  • Grew rate base by 17% and increased 5-year investment outlook by 20%

  • Executed agreement to acquire three water companies (pending)

    Operational and Customer Excellence

    ✓

  • Ranked #1 in the Northeast for

    customer trust

  • Achieved top-quartile reliability for the fourth consecutive year

  • Ranked among the top companies in

    the nation for emergency response

  • Maintained high levels of employee pride and engagement

  • Named one of the Best Companies

    to work for in New Hampshire

  • Solar project named 2025 NH Energy Week "Project of the Year"

    1. Adjusted EPS excludes non-recurring transaction costs. Adjusted Net Income and Adjusted EPS are non-GAAP financial measures. SLIDE 4

       
       
       Elevating the Customer Experience

       Driving satisfaction and loyalty through superior service

       Top Quartile Electric Reliability

       Four consecutive years of top quartile electric service reliability

       Best-in-Class Gas Emergency Response

       Ranked among the top companies in the nation for gas emergency response

       Pipeline Safety

       Management

       Selected as a "Best Practice Operator" at the American Gas Association's Best Practices Conference

       100%

       90%

       80%

       70%

       Overall Customer Satisfaction

       Unitil National Northeast

       2019 2020 2021 2022 2023 2024 2025

       SLIDE 5

       
       
       Sustainable Value Creation

       Securing our future through responsible action

       Governance

       Board Qualifications and Expertise

       Accounting CEO/C-Suite ESG/Sustainability

       Finance Governance IT/Cybersecurity Investor Relations

       Labor/HCM Legal/Public Policy Marketing/Customer Relations

       Risk Oversight Strategic Planning

       Utility Operations/Regulation

       0 2 4 6 8 10

       People

       Recognized as one of New Hampshire's "Best Companies to Work For" for the fourth consecutive year.

       SLIDE 6

       Kingston Solar Array

       2025 NH Energy Week "Project of the Year"

       Our solar facility in Kingston, New Hampshire is the largest solar energy project in the state of New Hampshire, producing enough electricity to power over 1,200 homes.

       5 MW

       photovoltaic (PV) solar facility

       9.7million

       kilowatt hours generated annually

       $2 million

       estimated savings for customers

       
       
       Accretive Expansion

       Accelerating growth through strategic acquisitions

       Enabling Value Creation

• Unitil now serves approximately 90% of natural gas customers in Maine

• Attractive service areas in major population centers

• Strong customer growth of 4% - 5% due to price advantage of natural gas and low penetration

• Fuel choice laws in place preserving the rights of consumers to select their preferred energy systems

• Strong geographic fit; highly complementary to existing operations

  Integration Status

• Bangor Natural Gas (Closed January 31, 2025)

  - Integration complete

• Maine Natural Gas (Closed October 31, 2025)

- I.T. Integration expected to be substantially complete May 1, 2026

SLIDE 7

Residential Fuel Price per MMBtu

$100

$G0

$80

$70

$60

$50

$40

$30

$20

$10

$-

Maine

Natural Gas

Massachusetts

Heating Oil

Propane

New Hampshire

Electricity

Natural gas is the smarter, cheaper alternative for home heating

The Natural Gas Advantage

$ per MMBtu

• Natural gas is the lowest-cost heating fuel in Maine, Massachusetts and New Hampshire

• Utility management of gas supply portfolios provides pricing stability not typical of petroleum-based fuels

• Gas heating systems are more cost-effective than electric heat

pumps due to cold temperatures and high electricity prices

Natural Gas vs. Heat Pump

$60

$50

Electric Heat Pump ($0.31 per kWh)

$40

$30

$20

Natural Gas Boiler ($1.80 per therm)

$10

$-

-15 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60

Outdoor Temperature (Fahrenheit)

Heat Pump Natural Gas

$ per MMBtu

Natural gas heating cost compared to other fuels…

Fuel Price Data: U.S. Energy Information Administration (EIA)

Prices shown are January 2026 with the exception of natural gas in Maine, which is December 2025 Residential natural gas data in Maine unavailable for January 2026

SLIDE 8

Converting homes to natural gas lowers energy costs and reduces emissions

Maine

2.2% 13.5%

8.3%

9.7%

16.0% 50.3%

Highest percentage of homes heated with fuel oil in the nation

New Hampshire

3.3% 11.9%

5.2%

20.4%

22.2%

37.0%

Source: Washington Post, March 6, 2023

Fuel switching to natural gas presents a major opportunity to improve energy affordability

Second highest percentage of homes heated with fuel oil in the nation

SLIDE 9

Complementary utility operations add scale and diversification supporting long-term growth

1. Rate base as of December 31, 2025, includes estimates and approximations that are typically settled or litigated in rate cases

   SLIDE 10

   
   
   Accelerating Growth

   Recent acquisitions are expected to be earnings accretive over the long-term

   Long-Term Guidance
   EPS Growth	5.0% - 7.0%
   Rate Base Growth	6.5% - 8.5%
   Total Shareholder Return	8.0% - 10.0%(1)

   Accelerating Rate Base Growth(2)

$2.5

$2.0

$1.5

$1.0

$0.5

$-

2024A 2025A 2026F 2027F 2028F 2029F 2030F

Billions

Acquisitions will accelerate long-term

EPS and Rate Base growth

17% Additional Rate Base

17% Additional Gas Customers

23,000 Water Customers in MA and NH

15%

Gas Margin Increase

SLIDE 11

Accelerating infrastructure modernization and expansion

$ in millions

$300

$250

$200

$150

Five-year capital investment of approximately $1.2 billion

835

~20% increase over previous 5-year forecast

1,400

$ in millions

1,200

1,000

800

600

400

200

0

8.1% CAGR

1,002

900

935

1,068

1,135

1,329

$100

$50

$170

$185

$221 $228 $229

$252 $254

2019 2020 2021 2022 2023 2024 2025

$0

2024 2025 2026F 2027F 2028F 2029F 2030F

1. Forecast does not include pending acquisition of three Aquarion water companies

2. 2025 consolidated rate base includes acquisitions of Bangor Natural Gas and Maine Natural Gas

3. Rate Base figures include estimates and approximations that are typically settled or litigated in rate cases

SLIDE 12

Maintaining a strong balance sheet is a strategic priority

CFFO, Less Dividends, 58%

Debt, 30%

Equity, 12%

Prioritizing Balance Sheet Stability

• Cash Flow from Operations funds the majority of capital

  investment

• Balanced mix of common equity and long-term debt offers financial flexibility

• Limited refinancing risk and no variable rate long-term debt

• Strong financial profile supports credit metrics well above

downgrade thresholds

1. Most recent data per S&P Ratings 360; includes S&P rating adjustments

   • Cash Flow From Operations, less dividends, funds majority of capital plan

   • Debt is net of any refinancing of maturing long-term debt

   • Equity includes funds raised through the Unitil Dividend Reinvestment Plan and external equity issuances

SLIDE 13

Historical earnings growth at long-term guidance midpoint

$3.50

$3.16

$2.82

$2.97

$2.59

$2.23

$2.31

$2.35

$2.15

$1.79

$1.89

$1.94

$2.06

$1.57

8.6% Annual Growth

Net Utility Plant

7.2% Annual Growth

Common Stock Equity

7.3% Annual Growth

Net Income

6.0% Annual Growth

Earnings Per Share

$3.00

$2.50

$2.00

$1.50

$1.00

$0.50

$-

2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025

1. 2019 excludes after-tax gain on the divestiture of Usource

2. 2024 and 2025 exclude transaction costs associated with the acquisitions of Bangor Natural Gas and Maine Natural Gas. Adjusted Net Income and Adjusted EPS are non-GAAP financial measures

   SLIDE 14

   
   
   Compelling Value Proposition

   Driving sustainable growth through a disciplined, regulated strategy

   5% - 7%

   Annual EPS Growth

   Long Term Guidance

   $1.2 Billion

   5-Year Utility Capex Plan(2)

   55% - 65%

   Dividend Payout Ratio

   Target Range

   6.5% - 8.5%

   Rate Base Growth(2)

   8% - 10%

   Annual Total Return(1)

   Price Appreciation Plus Dividend

   16% - 18%

   FFO/Debt Target

   1. Total Shareholder Return assumes dividend yield of 3.0%, growth of 5% - 7%, and a constant Price-to-Earnings ratio

   2. Forecasts of capital investments and rate base growth do not include acquisition of Aquarion water companies

SLIDE 15

Thank You!

Unitil Corporation

6 Liberty Lane West Hampton, NH 03842-1720

1-888-301-7700

www.unitil.com

NYSE Ticker: UTL

unitil.com/investors

Investor Relations

800-999-6501

InvestorRelations@unitil.com

86,600

Natural Gas Customers

SLIDE 17

Twelve months ended December 31, 2025

Twelve Months Ended December 31, 2025 ($ millions)

Twelve Months Ended December 31, 2024 ($ millions)

SLIDE 18

Twelve months ended December 31, 2025

(Millions, except per share data)

Twelve Months Ended December 31, 2025

Amount Per Share

GAAP Net Income Transaction Costs Adjusted Net Income

GAAP Net Income Transaction Costs Adjusted Net Income

$ 50.2 $ 2.97

3.1 0.19

$ 53.3 $ 3.16

Twelve Months Ended December 31, 2024 Amount Per Share

$ 47.1 $ 2.93

0.7 0.04

$ 47.8 $ 2.97

SLIDE 19